Project description:Differentiating pluripotent cells from fibroblast progenitors is a potentially transformative tool in personalized medicine. We previously identified relatively greater success culturing dura-derived fibroblasts than scalp-derived fibroblasts from postmortem tissue. We hypothesized that these differences in culture success were related to epigenetic differences between the cultured fibroblasts by sampling location, and therefore generated genome-wide DNA methylation and transcriptome data on 11 intrinsically matched pairs of dural and scalp fibroblasts from donors across the lifespan (infant to 85 years). While these cultured fibroblasts were several generations removed from the primary tissue and morphologically indistinguishable, we found widespread epigenetic differences by sampling location at the single CpG (N=101,989), region (N=697), “block” (N=243), and global spatial scales suggesting a strong epigenetic memory of original fibroblast location. Furthermore, many of these epigenetic differences manifested in the transcriptome, particularly at the region-level. We further identified 7,265 CpGs and 11 regions showing significant epigenetic memory related to the age of the donor, as well as an overall increased epigenetic variability, preferentially in scalp-derived fibroblasts -83% of loci were more variable in scalp, hypothesized to result from cumulative exposure to environmental stimuli in the primary tissue. By integrating publicly available DNA methylation datasets on individual cell populations in blood and brain, we identified significantly increased inter-individual variability in our scalp- and other skin-derived fibroblasts on a similar scale as epigenetic differences between different lineages of blood cells. Lastly, these epigenetic differences did not appear to be driven by somatic mutation - while we identified 64 probable de-novo variants across the 11 subjects, there was no association between mutation burden and age of the donor (p=0.71). These results depict a strong component of epigenetic memory in cell culture from primary tissue, even after several generations of daughter cells, related to cell state and donor age.
Project description:Differentiating pluripotent cells from fibroblast progenitors is a potentially transformative tool in personalized medicine. We previously identified relatively greater success culturing dura-derived fibroblasts than scalp-derived fibroblasts from postmortem tissue. We hypothesized that these differences in culture success were related to epigenetic differences between the cultured fibroblasts by sampling location, and therefore generated genome-wide DNA methylation and transcriptome data on 11 intrinsically matched pairs of dural and scalp fibroblasts from donors across the lifespan (infant to 85 years). While these cultured fibroblasts were several generations removed from the primary tissue and morphologically indistinguishable, we found widespread epigenetic differences by sampling location at the single CpG (N=101,989), region (N=697), “block” (N=243), and global spatial scales suggesting a strong epigenetic memory of original fibroblast location. Furthermore, many of these epigenetic differences manifested in the transcriptome, particularly at the region-level. We further identified 7,265 CpGs and 11 regions showing significant epigenetic memory related to the age of the donor, as well as an overall increased epigenetic variability, preferentially in scalp-derived fibroblasts -83% of loci were more variable in scalp, hypothesized to result from cumulative exposure to environmental stimuli in the primary tissue. By integrating publicly available DNA methylation datasets on individual cell populations in blood and brain, we identified significantly increased inter-individual variability in our scalp- and other skin-derived fibroblasts on a similar scale as epigenetic differences between different lineages of blood cells. Lastly, these epigenetic differences did not appear to be driven by somatic mutation - while we identified 64 probable de-novo variants across the 11 subjects, there was no association between mutation burden and age of the donor (p=0.71). These results depict a strong component of epigenetic memory in cell culture from primary tissue, even after several generations of daughter cells, related to cell state and donor age.
Project description:Aging signatures developed from a longitudinal study design are dominated by reduced transcription of genes involved in protein synthesis. Aging is a multifactorial process where the impact of singular components still remains unclear. Furthermore, previous studies were focused on measuring specific traits such as DNA -methylation and used categorical group-wise designs, unable to capture intra-individual signature changes. Here we have developed a new method for a longitudinal, age-related analysis combining the merits of a pair-wise design with the statistical power of gene set enrichment analysis. We present an integrated analysis, including transcriptional changes and genome-wide epigenetic changes in DNA- methylation, H3K4- and H3K27- histone methylation in promoter regions. We tested our method on a rare collection of paired skin fibroblast samples from male middle age to old age transitions and obtained functional, age-related clusters. By using a set of only ten individuals, we could demonstrate a high overlap of functional terms to previously established tissue-independent age signatures including extracellular matrix, apoptosis and oxidative stress. Importantly, we identify protein translation-related processes as the main cluster of age-driven, specific down regulation. H3K4me3, H3K27me3 and DNA- methylation longitudinal aging profiles from primary skin fibroblasts from matched pairs of early (E) and late (L) stages in life.
Project description:In the project “A Dual-Acting Nitric Oxide Donor and Phosphodiesterase 5 Inhibitor Activates Autophagy in Primary Skin Fibroblasts» by Esther Martínez-Martínez and Joern Dengjel, we performed expression proteomics analyzing the response of normal human fibroblasts (NHF) isolated from healthy skin to the drug TOP-N53.
Project description:Background: Skin homeostasis is mediated by dermal fibroblasts and is affected by aging. Although age-related heterogeneity in fibroblasts has been reported, the effects of donor and species on this heterogeneity are unclear. Methods: To analyze age-related transcriptomic changes in human dermal fibroblasts, single-cell RNA sequencing was performed on dermal fibroblasts (ASF-4 cells) collected from the inner forearm of a volunteer over three decades. Results: Four main cell subpopulations changed with donor age and showed proliferative, homeostasis, fibrotic, and senescence functional annotations. The downregulation of the expression of genes encoding key extracellular matrix production and mechanotransduction components decreased with donor age. Interestingly, dermal fibroblasts have two putative differentiation pathways: one that involves the acquisition of senescent properties and the acquisition of fibrotic properties without the suppression of proliferation. Aging induced fibroblast differentiation in a manner involving the acquisition of senescent properties. Conclusion:Reconciling the various aspects of fibroblast heterogeneity may provide insight into the mechanisms underlying human skin aging and associated phenomena, including wrinkles, sagging, delayed wound healing, and suppressed scar formation.
Project description:Choroideremia (CHM) is a progressive X-linked retinopathy caused by mutations in the CHM gene, which encodes Rab escort protein-1 (REP-1), an escort protein involved in the prenylation of Rabs. Under-prenylation of certain Rabs, as a result of loss of function mutations in REP-1, could affect vesicular trafficking, exocytosis and secretion. To evaluate this hypothesis, intracellular vesicle transport, lysosomal acidification and rates of proteolytic degradation were studied in monocytes (CD14+ fraction) and primary skin fibroblasts from the nine age-matched controls and thirteen CHM patients carrying 10 different loss-of-function mutations. expression data were collected from 6 CHM patients' monocytes and 4 CHM primary fibroblasts cultures, monocytes or FB from 5 normal age-matched subjects were used as a control
Project description:Normal fibroblasts and SSc fibroblasts between the third and six subpassages were used for experiments. Total RNA was extracted from culture cells with ISOGEN (Nippon Gene, Tokyo, Japan). MicroRNA isolation from total RNA was performed using RT2 qPCR-Grade miRNA Isolation Kit (SA Bioscience). For RT2 Profiler PCR Array (SABioscience), microRNAs were reverse-transcribed into first strand cDNA using RT2 miRNA First Strand Kit (SABiosciences). A mixture of equal amounts of cDNAs from 5 normal fibroblasts or 5 SSc fibroblasts was prepared. The cDNA was mixed with RT2 SYBR Green/ROX qPCR Master Mix and the mixture was added into a 96-well RT2 miRNA PCR Array (SABiosciences) that included primer pairs for 88 human microRNAs. Human dermal fibroblasts were obtained by skin biopsy from the affected areas (dorsal forearm) of 5 patients with diffuse cutaneous SSc and <2 years of skin thickening. Control fibroblasts were obtained by skin biopsies from 5 healthy donors. Control donors were each matched with a SSc patient for age, sex, and biopsy site.
Project description:Aging signatures developed from a longitudinal study design are dominated by reduced transcription of genes involved in protein synthesis Aging is a multifactorial process where the impact of singular components still remains unclear. Furthermore, previous studies were focused on measuring specific traits such as DNA -methylation and used categorical group-wise designs, unable to capture intra-individual signature changes. Here we have developed a new method for a longitudinal, age-related analysis combining the merits of a pair-wise design with the statistical power of gene set enrichment analysis. We present an integrated analysis, including transcriptional changes and genome-wide epigenetic changes in DNA- methylation, H3K4- and H3K27- histone methylation in promoter regions. We tested our method on a rare collection of paired skin fibroblast samples from male middle age to old age transitions and obtained functional, age-related clusters. By using a set of only ten individuals, we could demonstrate a high overlap of functional terms to previously established tissue-independent age signatures including extracellular matrix, apoptosis and oxidative stress. Importantly, we identify protein translation-related processes as the main cluster of age-driven, specific down regulation. Evaluation of transcriptional changes in matched sample pairs of primary skin fibroblasts from middle and old age.